PCV valve guide

ABSTRACT

A positive crankcase ventilation valve assembly including a housing having a fluid inlet and outlet. A poppet valve is arranged in the housing between the fluid inlet and outlet and is movable in a axial direction between a plurality of positions. The positions respectively define a plurality of fluid flow rates. A plurality of ribs extend radially from either the poppet valve and the housing in an axial direction. The ribs define a bearing surface between the housing and the poppet valve. In this manner, the poppet valve is supported within the housing with a reduced bearing surface area while aligning the poppet valve relative to the housing throughout its movement between the positions. In another embodiment, the poppet valve is eliminated to prevent problems associated with an improperly operating poppet valve. A diaphragm is arranged in the housing between the fluid inlet and outlet. The diaphragm has an orifice, which may be defined by a hole and a plurality of slots extending outwardly from the hole, defining first and second areas, respectively, in first and second positions. The first and second positions respectively define first and second fluid flow rates. The diaphragm moves axially in response to pressure fluctuations on the valve, which changes the area of the orifice to vary the flow rate through the orifice.

RELATED APPLICATIONS

[0001] The application claims priority to U.S. Provisional ApplicationNo. 60/380,799, which was filed on May 15, 2002.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to positive crankcase ventilation(PCV) valve assemblies, and more particularly, the invention relates tothe mechanism controlling the flow through the PCV valve.

[0003] PCV valve assemblies are used to vent unburned combustion gases,which blows by the piston rings and into the engine crankcase, to theintake manifold to be burned. Release of pressure within the crankcaseand burning the unburned combustion gases are critical to obtaindesirable engine operation and emissions. Numerous PCV valve actuationdevices for opening and closing the valve have been proposed, some ofwhich do not provide valve control to the degree desired.

[0004] Some PCV valve assemblies incorporate a poppet valve that movesaxially within a valve housing between positions to vary the flowthrough the PCV valve. The valve assembly is subject to vibrations fromthe vehicle and engine, which may inhibit the proper operation of thevalve. For example, a poppet valve body may engage an inner surface ofthe housing as it moves between the positions. The vibrations may causethe poppet to be skewed along its axis as it moves between the positionsthereby binding up in an undesired position due to the large contactsurface area between the valve and the housing. As a result, the desiredamount of flow may not be provided through the PCV valve and anundesirable noise may occur from the malfunctioning valve assembly.Therefore, what is needed is an improved valve control device providingmore consistent operation of the valve to obtain the desired flowthrough the PCV valve.

SUMMARY OF THE INVENTION AND ADVANTAGES

[0005] The present invention provides a positive crankcase ventilationvalve assembly including a housing having a fluid inlet and outlet. Apoppet valve is arranged in the housing between the fluid inlet andoutlet and is movable in a axial direction between a plurality ofpositions. The positions respectively define a plurality of fluid flowrates. A plurality of ribs extend radially from either the poppet valveand the housing in an axial direction. The ribs define a bearing surfacebetween the housing and the poppet valve. In this manner, the poppetvalve is supported within the housing with a reduced bearing surfacearea while aligning the poppet valve relative to the housing throughoutits movement between the positions.

[0006] In another embodiment, the poppet valve is eliminated to preventproblems associated with an improperly operating poppet valve. Adiaphragm is arranged in the housing between the fluid inlet and outlet.The diaphragm is movable in an axial direction between first and secondpositions. The diaphragm has an orifice, which may be defined by a holeand a plurality of slots extending outwardly from the hole definingfirst and second areas, respectively, in first and second positions. Thefirst and second positions respectively define first and second fluidflow rates. The diaphragm moves axially in response to pressurefluctuations on the valve, which changes the area of the orifice to varythe flow rate through the orifice.

[0007] Accordingly, the above invention provides an improved valvecontrol device providing more consistent operation of the valve toobtain the desired flow through the PCV valve.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Other advantages of the present invention can be understood byreference to the following detailed description when considered inconnection with the accompanying drawings wherein:

[0009]FIG. 1 is a perspective view of a PCV valve;

[0010]FIG. 2 is a cross-sectional view of the PCV valve shown in FIG. 1;

[0011]FIG. 3 is an end view of the PCV valve shown in FIG. 2;

[0012]FIG. 4 is a cross-sectional view of the first housing portion ofthe PCV valve shown in FIG. 2;

[0013]FIG. 5 is an end view of the first housing portion shown in FIG.4;

[0014]FIG. 6 is a side view of the poppet valve shown in FIG. 2;

[0015]FIG. 7 is an end view of the second portion of the poppet valveshown in FIG. 6;

[0016]FIG. 8 is a side view of another poppet valve for use with the PCVvalve shown in FIG. 1;

[0017]FIG. 8A is a cross-sectional view of the first portion of thepoppet valve shown in FIG. 8 taken along lines 8A-8A;

[0018]FIG. 9 is a perspective view of another PCV valve;

[0019]FIG. 10 is a cross-sectional view of the PCV valve shown in FIG.9; and

[0020]FIG. 11 is an end view of the PCV valve shown in FIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0021] A PCV valve is shown at 10 in FIG. 1. The PCV valve 10 includes ahousing 12 having an inlet 14 and an outlet 16 with a fluid passagearranged between the inlet 14 and outlet 16. A poppet valve 18 isarranged in the housing 12 between the inlet 14 and outlet 16. A spring20 is disposed within the housing 12 and biases the poppet valve 18 to adesired position. In response to a changes in pressures acting on thepoppet valve 18, the spring 20 becomes compressed permitting increasedflow through the valve 10. An orifice plate 22 may be arranged betweenfirst 24 and second 26 housing portions to define a flow rate throughthe valve 10 in conjunction with the poppet valve.

[0022] To ensure smooth and uninhibited travel of the poppet valvebetween positions and to limit the effects of vibration on the PCVvalve, specialized bearing surfaces between the poppet valve 18 and thehousing 12 may be utilized, as best shown in FIGS. 2-5. The poppet valve18 may include first 28 and second 30 poppet portions. Ribs 32 mayextend inwardly from the first housing portion 24 to support the firstpoppet portion 28 by bearing surfaces 34 which define the contact areabetween the poppet valve 18 and the housing 12. The ribs 32 may includetapered leading edges 33 to facilitate insertion of the poppet valve 18into the first housing portion 24 during assembly of the valve 10. Asbest shown in FIGS. 6 and 7, the second poppet portion 30 may include ahead with corners 36 defining a second set of ribs that engage thesecond housing portion 26 defining a second bearing surface. In thismanner, both the first 28 and second 30 poppet portions are supported inthe housing 12 by reduced area bearing surfaces that guide the poppetvalve 18 within the housing 12 during travel between positions. Theflats between the corners 36 of the head permits partial fluid flowthrough the valve 10 when the spring 20 biases the poppet valve 18axially against the housing 12.

[0023] As an alternative to using the ribs 32 extending from the firsthousing portion 24, the first portion of the poppet valve 38 may includeribs 24 extending from the first poppet portion 40, as shown in FIGS. 8Aand 8B. The second poppet portion 42 may include ribs or corners or maybe supported by a second housing portion having ribs.

[0024] The problem of poppet valves sticking within the housing is alsoaddressed by the PCV valve 50, shown in FIG. 9. The PCV valve 50includes an inlet 51 and an outlet 52. The valve 50 includes first 53and second 54 housing portions secured to one another. A first 56 andsecond 58 diaphragm may be retained between the housing portions 53 and54, which together define the flow rate through the valve 50. A seal 60may be used between the diaphragms 56 and 58 to retain and actuallylocate the diaphragms within the housing portions 53 and 54.

[0025] The diaphragm deflects in response to pressure fluctuations. Thefirst 56 and second 58 diaphragms respectively include first 62 andsecond 64 orifices that define the flow rates for the various positionsof the diaphragms. The diaphragms have different orifices sizes andrespond differently to pressure fluctuations on the valve 50. The firstorifice 62 is defined by a hole 66 having slots 68 extending from thehole 66, as best shown in FIG. 11. The second orifice 64 includes a hole70 with slots 72 extending from the hole 70. The slots 68 and 70 betterenable the area defined by the orifices to be varied as the diaphragmsflex between positions. In one position, the diaphragms have afrustoconical cross-section, as best shown in FIG. 10. The firstdiaphragm 56 is shown in a flatter position than the second diaphragm58. As the diaphragms flatten, the area of the orifice is decreasedthereby decreasing the flow rate through the valve 50. One or morediaphragms may be used in the present invention PCV valve.

[0026] The invention has been described in an illustrative manner, andit is to be understood that the terminology that has been used isintended to be in the nature of words of description rather than oflimitation. Obviously, many modifications and variations of the presentinvention are possible in light of the above teachings. It is,therefore, to be understood that within the scope of the appended claimsthe invention may be practiced otherwise than as specifically described.

What is claimed is:
 1. A positive crankcase ventilation valve assemblycomprising: a housing having a fluid inlet and outlet; a poppet valvedisposed in said housing between said fluid inlet and outlet and movablein an axial direction between a plurality of positions respectivelydefining a plurality of fluid flow rates; and a plurality of ribsextending radially from one of said poppet valve and said housing insaid axial direction, said ribs defining a bearing surface between saidhousing and said poppet valve.
 2. The assembly according to claim 1,wherein ribs extend radially from said housing.
 3. The assemblyaccording to claim 2, wherein housing includes first and second housingportions secured to one another about said poppet valve.
 4. The assemblyaccording to claim 3, wherein said poppet includes first and secondpoppet portions with said first poppet portion supported by said ribs onsaid first housing portion and said second poppet portion supported bysaid second housing portion.
 5. The assembly according to claim 4,wherein said second poppet portion includes a second plurality of ribsdefining a second bearing surface between second poppet portion and saidsecond housing portion.
 6. The assembly according to claim 5, whereinsaid second ribs are defined by corners arranged circumferentially aboutsaid second poppet portion.
 7. The assembly according to claim 1,wherein a spring is engages said poppet valve biasing said poppet valvefrom said first position to said second position.
 8. The assemblyaccording to claim 1, wherein said ribs include a tapered leading edgefacilitating insertion of said poppet valve during assembly.
 9. Apositive crankcase ventilation valve assembly comprising: a housinghaving a fluid inlet and outlet; and a diaphragm disposed in saidhousing between said fluid inlet and outlet and movable in an axialdirection between first and second positions, said diaphragm having anorifice having first and second areas respectively in first and secondpositions defining first and second fluid flow rates respectively. 10.The assembly according to claim 9, wherein said diaphragm has afrustoconical cross-section in said first position and a flattercross-section than said frustoconical cross-section in said secondposition, said first area and flow rate being greater than said secondarea and flow rate.
 11. The assembly according to claim 9, wherein saidorifice is a hole with slots extending outwardly from said hole.
 12. Theassembly according to claim 9, wherein a second diaphragm is spacedradially from said diaphragm between said fluid inlet and outlet andmovable in an axial direction between third and fourth positions, saidsecond diaphragm having an second orifice having third and fourth areasrespectively in third and fourth positions defining third and fourthfluid flow rates respectively.
 13. The assembly according to claim 12,wherein said housing includes first and second housing portions securedto one another with a seal arranged between said first and secondhousing portions between said diaphragms.